package model;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: ASUS
 * Date: 2024-01-15
 * Time: 14:17
 */
//通过BlogDao来完成针对blog表的操作
public class BlogDao {
    //1.新增操作（提交博客就会用到）
    public void insert(Blog blog){
        Connection connection = null;
        PreparedStatement statement = null;

        try{
            //1.建立连接
           connection = DBUtil.getConnection();
            //2.构造sql语句
            String sql = "insert into blog values(null,?,?,now(),?)";
            statement = connection.prepareStatement(sql);
            statement.setString(1, blog.getTitle());
            statement.setString(2, blog.getContent());
            statement.setInt(3,blog.getUserId());
            //3.执行SQL
            statement.executeUpdate();

        }catch (SQLException E){
            throw new RuntimeException();
        }finally {
            DBUtil.close(connection,statement,null);
        }
    }
    //2.查询博客列表（博客列表页）
    //把数据库里所有的博客都拿到
    public List<Blog> getBlogs(){
        List<Blog> blogList = new ArrayList<>();
        Connection connection =null;
        PreparedStatement statement = null;
        ResultSet resultSet = null;
        try{
            connection = DBUtil.getConnection();
            String sql = "select * from blog order by postTime desc";
            statement = connection.prepareStatement(sql);
            resultSet = statement.executeQuery();
            while(resultSet.next()){
                Blog blog = new Blog();
                blog.setBlogId(resultSet.getInt("blogId"));
                blog.setTitle(resultSet.getString("title"));
                //简单的截断
                String content = resultSet.getString("content");
                if(content.length() > 100){
                    content = content.substring(0,100)+"...";
                }
                blog.setContent(content);
                blog.setPostTime(resultSet.getTimestamp("postTime"));
                blog.setUserId(resultSet.getInt("userId"));
                blogList.add(blog);
            }
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }finally {
            DBUtil.close(connection,statement,resultSet);
        }
        return blogList;
    }
    //3.根据博客 id查询指定博客
    public Blog getBlog(int blogId){
        Connection connection = null;
        PreparedStatement statement = null;
        ResultSet resultSet = null;
        try {
            connection = DBUtil.getConnection();
            String sql = "select * from blog where blogId = ?";
            statement = connection.prepareStatement(sql);
            statement.setInt(1,blogId);
            resultSet = statement.executeQuery();

            //此处拿着blogId进行查询，为主键且唯一，不需要使用while
            if(resultSet.next()){
                Blog blog = new Blog();
                blog.setBlogId(resultSet.getInt("blogId"));
                blog.setTitle(resultSet.getString("title"));
                //详情页
                blog.setContent(resultSet.getString("content"));
                blog.setPostTime(resultSet.getTimestamp("postTime"));
                blog.setUserId(resultSet.getInt("userId"));
                return blog;
            }
        } catch (SQLException e) {
            throw new RuntimeException(e);

        }finally {
            DBUtil.close(connection,statement,resultSet);
        }
        return null;
    }

    //4.根据博客 id，删除博客
    public void delete(int blogId){
        Connection connection = null;
        PreparedStatement statement = null;
        try{
            connection = DBUtil.getConnection();
            String sql = "delete from blog where blogId = ?";
            statement = connection.prepareStatement(sql);
            statement.setInt(1,blogId);
            statement.executeUpdate();
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }finally {
            DBUtil.close(connection,statement,null);
        }
    }

}
